Railway-traffic-controlling apparatus



g 1930'. L. NETTLETON 1,772,781

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed March 8, 1929 v INVENTOR: j L.A..Nctt/ton,

AA, ATTORNEY Patented Aug. 12, 1930 weep; smi e PATENT times tewrs nnsrrterou pr enerwoot iseaocenureuusrtvmii, assxeuoa To Uri-ION SWITCH 8c SIGNALCOMPAITY, 6F SWISSVAL'E, PENNSYZVANIA, A CORPORA- TION' Oi PEfiNSYiVANiA RAILWAY-TnArFIo-ooN'rRoLLInG APPARATUS Application filed March 8,

My invention relates to railway traflic controlling apparatus, and particularly to apparatus of the type involving means for supplying electrical energy to the track rails and train carried governing inechanisin controlled by energy received from the track rails. One feature of my invention is the provision of means for periodically supplying direct currentto the track rails, andtrain carried governing mechanism controlled by the direct current in the rails.

I will describe two forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a diagrammatic view showing one form of apparatus embodying my invention. Fig. 2 is a view showing a modification of a portion of the apparatus shown in Fig. 1 and also embodying my invention. Figs. 3 and dare Views showing certain characteristics of the apparatus shown in Figs. 1 and 2.

Similar reference characters refer to similar parts in each of the views.

Referring first to Fig. 1, the reference characters 1 andl designate the track-rails of a railway track along which traffi'c nor mally moves in the direction indicated by the arrow. These rails are periodically supplied with direct current from a battery B, through the medium of a coding device designated by the reference characterC.

V The coding device C comprises an electric motor constantly supplied with current from battery B, and three cams 3 3 and 3 operatively connected with-the motor 2. These cam's' operatecontacts 4 4 and 4 respectively, and the cams are provided with difi'er ent numbers of swells, so that the three contacts are operated at-diiferent frequencies.

I For example, Contact 4? maybe opened and closed 180 times per minute, contact 5t", 120 times per minute, andcontact 4, 80 times per minute. The battery B is connected across the rails 1 and 1 through contact 4 'or 4, according as a movable contact member 5 is in engagement with a fixed contact 5, 5 'or 5.

The movable ontactmemberfi may be operated by any suitable means, such. for example,

1929. Serial No. 345 327.

as by traffic conditions in advance, but the means for operating, this contact member forms no part of my present invention and comprising a pair of magnetizable cores 6 and 6 provided with windings-7 and 7 respectively, which are located in inductive relation to the two track rails 1 and 1 respectively. These windings are connect-ed in series in a receiving circuit E in such manner that the currents induced therein by changes in the value of the current in the track rails from battery B are additive. The terminals of the receiving circuit E are connected with the primary of a transformer T. The reference character A designates a train carried amplifier of the well known electron tube type having a filament 7, a grid Sand a plate 9. The filament 7 is constantly heated by a battery 13, through resistances 14 and 15. The terminals of the secondary of transformer T are connected with the filament and grid'respectively of theamplifier A, resistance 15 being interposed between one terminal of the'secondary andfil'ament 7.- The amplifier A is provided with a plate circuit which passes from terminal B of a source of direct current, through a resistance elemeIit 27, the amplifier tube A, and resistance 14 to terminal 0 of the same source of current. p

The reference character G designates a tube characterized by a normally high resistance whichbecomes greatly reduced when the voltage applied to the tube exceeds a given value. In the form shownin .Fig. 1 this tube is of the grid glow variety-having an anode 10, a grid 11 and a cathode or plate 12. The anode 10 and grid 11 0f the tube G are'connected'to the-plate circuit of the amplifier A at opposite ends of the; resistance element 27-respectively, the -anode beingconnected at the positive end of this element and the grid lltbeingconnected at thenegative end. The platecircuit for the tubeG passes (from terminaLB, through the anode and cathode of the tu e, h Winding tilt? of a relay R back contact 16 of a relay R, and resistance 14 to terminal 0 of the source of plate current. It will be seen, therefore, that the voltage across the resistance element 27 in the plate circuit of the amplifier A is impressed between the anode and grid of the tube G, and that the voltage across the amplifier tube A is impressed between the grid 11 and the cathode 12 of the tube G. Under normal conditions, that is, with no voltage impressed on the receiving circuit E, the grid bias and the plate voltage of the am plifier tube A are of such values that the grid 11 of the tube G is sufficiently negative with respect to the anode 10 to prevent this tube from being conductive, that is, to prevent it from breaking down. If, then, a negative impulse is impressed on the grid of the amplifier A, the amplifier plate current will decrease, the voltage across the resistance element 27 will decrease, and the voltage across the amplifier tube A will increase. This re sults in reducing the negative potential on the grid 11 of the grid glow tube G with respect to the potential applied to the anode 10, with the result that the tube G breaks down, that is, the resistance of its plate circuit becomes greatly reduced. The voltage between the grid 11 and the cathode 12 needs to reach a value greater than the break down voltage for only an extremely short time interval to cause the tube G to break down, and once the break down is accomplished current will continue to flow through the plate circuit of the grid glow tube until it is in terrupted at some other point. This flow of current causes relay R to become energized, and when the front contact 17 of relay R closes, the circuit for the second relay B becomes closed, which circuit is obvious from the drawing. As soon as the back contact 16 of relay R opens, the plate circuit for tube G becomes opened, so that relay R is again de-energized. The opening of relay R of course, opens the circuit for the relay R so that the latter relay also becomes deenergized, and these two relays are then re-' stored to their initial positions.

Relays R and B may be employed to control train governing apparatus of any suitable kind. As here shown, these relays control a polarized master relay R having a polarized armature 20 and two windings 21 and 22 arranged when energized to swing the armature to its oposite extreme positions. One or the other of these windings is included in the circuit for the relay R according as the armature is swung to one position or the other. Assuming that armature 2O is in the position shown in the drawing, then when relay R becomes closed, the circuit for relay R is from terminal B of a suitable source of current, through front contact 18 of relay R, back contact 19 of relay R armature 2O of relay R contact 24, and winding 22 to terminal 0 of the same source of current. Winding 22 causes the armature 20 to swing to the left, whereupon contact 20-23 becomes closed to connect winding 21 in the circuit for relay R WVinding 21 when supplied with current will cause the armature 20 to return to its right-hand position, but contact 19 of relay R opens before contact 21 has an opportunity to influence the armature 20. It will be seen, therefore, that the next impulse due to the closing of contact 18 of relay R will restore armature 20 of relay R to its right-hand position. In other words, successive impulses will result in successive operation of armature 20 to its opposite extreme positions, and the rate of operation of this armature will of course be determined by which one of contacts 1 is interposed between battery B and track rail 1 Contacts 25 and 26 of relay B may be employed to control suitable train governing apparatus, such for example, as the apparatus shown in application for Letters Patent of the United States filed by P. N. Bossart on February 7, 1927, Serial No. 166407. That is to say, the apparatus controlled by the master relay R- in the said Bossart application may be controlled by the master relay R in the present application.

Referring now to Fig. 3, T have indicated by curves the conditions existing in the different parts of the apparatus shown in Fig. 1 during the periodic supply of direct current from the battery B to the track rails. It will be seen from Fig. 3 that each time one of the contacts t closes (curve a) so that current begins to'fiow in the track rails (curve 2)), a momentary voltage is induced in the receiver circuit E (curve 0), and that each time one of the contacts 4; opens (curve a) so that current ceases to flow in the track rails (curve 6), a momentary voltage is induced in the opposite direction in the receiv ing circuit E (curve 0). Each impulse of voltage in the receiving circuit E causes a full wave impulse in the current flowing in he plate circuit of amplifier A (curve (Z), and this causes a full wave impulse in the voltage applied to the grid glow tube G (curve 0), whereupon this tube breaks down and current flows through it (curve 7). Relay R then picks up (curve g), after which relay R picks up (curve it), and during the interval between the closing of relay R and the closing of rel y (curve 2') one of the windin s 21 or 22 of relay R is energized, so that this relay is reversed (curve In the curves shown in Fig. 3, I have assumed that the track current is on for onehalf the time and off for the other half of the time. The same results may be achieved by supplying current to the track rails periodically for only very shortintervals of time, and the characteristics of the apparatus when this is on are shown in Figt- Th ar /aver operation under the cone 't ions "shown in Fig. 4, will be understood fr-cm the foregoing discussion without further explanation.

Referring now to F 2, tie apparatus is the same as that shown in Fig. 1 except that a neon tube is substituted for the grid glow tube G. The terminals of the neon tube are connected across the resistance element 27 through the winding of relay R and back contact 16 oi' relay RF. Assuming for example that the neontube will break down ii the'diilerence of potential across its termi nals reaches 200 volts, and that the normal adjustment of the amplifier A is such that the diiierence of potential across resistance 2? is 150 volts, then if the grid potential or" the amplifier Ais increased for an instant by a value sufficient to cause the current in the plate circuit to increase to such amount that diiierenceof potential across the resistanceeleine'nt :27 equals 200 volts, the neon tube will break down and relay R will be come energized. As soon as relay R becomes energized due to the closing of relay R the circuit for the neon tube will be opened at contact 16 and so the resistance or". the neon tube will again rise to its normal Value. V

Considering now both Figs. 1 and 2, since the grid glow tube or the neon tube takes no power until it breaks down, it does not take power from the amplifier A until it operates, and, consequently, voltage amplification is all that is required, that is to say, power amplification is unnecessary. The amplifier tube A may, therefore, have a high amplification factor, and this factor may easily be made 100, particularly if two amplifier tubes are connected in cascade. Under these conditions, the voltage required in the receiving circuit E need be only about onehalt' volt, and such voltage may easily be obtained by a single impulse of direct current in the track rails.

Although I have herein shown and described only two forms of apparatus enibodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway trafic controlling apparatus comprising means for periodically supplying direct current to a track rail, 2. train carried receiver winding located in inductive relation to said rail, an amplifier having its input circuit connected with said receiver winding, an output circuit for said amplifier including a resistance element, a tube connected across said resistance element and characterized by a normally high resistance which becomes greatly reduced when the voltage applied to the tube exceeds a given value, a relay corn nectd with said tube and normally de-enen 'gized but energized when the resistance of said tube is reduced, and train governing apparatus controlled by said relay.

2. Railway trafiic controlling apparatus comprising means for periodically supplying direct current to a track rail, a train carried receiver winding located in inductive relation to said rail, an amplifier having its input cir cuit connected with said receiver winding, an output circuit for said amplifier including a resistance element, a grid glow tube having its anode and grid connected across said resist'an'ce element, a plate circuit for said tube including a relay, a second relay having a back contact included in the circuit for said first relay, a circuit for'said second relay controlled by a front contact of said first relay, and train governing apparatus controlled by said'relays. I

3. Railway tratfic controlling apparatus comprising means for periodically supplying direct current to a track rail, a train carried receiver winding located in inductive relation to said rail, an amplifier having its input circuit connected with said receiver winding, an output circuit for said amplifier including a resistance element, a grid glow tube having its anode and grid connected across said resistance element, a plate circuit for said tube including a'relay, a second relay having a back contact included in the circuitfor said first relay, a circuit for said second relay controlled by a front contact of said first relay, a polarized train governing master relay havin g two windings arranged when energized to swing the armature to opposit'e'pos'itions, a circuit for said master relay including i a front contact of said first relay and a back contact of said second relay, and means operating when the armature of said master relay is swung to either position to connect into the circuit for such relay the winding which swings the armature to the other position.

4. Railway trafiic controlling apparatus comprisingnieans for periodically supplying direct current to a track rail, a train carried receiver winding located in inductive relation to said rail,an amplifier having its input circuit connected with said receiver winding, an'output circuit for said amplifier including a resistance element, a tube connected across said resistance element and characterized by a normally high resistance which becomes greatly reduced when the voltage applied to the tube exceeds agivenvalue, a relay connected with said tube and nom nall deenergized but energized when the resistance of said tube is reduced, :a secondrelay having a back contact included'in the circuit for said first relay, acircuit for said second relay controlled by a front contact of said first relay, and train governing apparatuscontrolled by said relays;

5. Railway trafiiccontrolling apparatus comprising means for periodically supplying direct current to a track rail, a train carried receiver winding located in inductive relation to said rail, an amplifier having its input circuit connected with said receiver winding, an output circuit for said amplifier including a resistance element, a tube connected across said resistance element and characterized by a normally high resistance which becomes greatly reduced when the voltage applied to the tube exceeds a given value. a relay connected with said tube and normally de-energized but energized when the resistance of said tube is reduced, a second relay having a back contact included in the circuit for said first relay, a circuit for said second relay controlled by a front contact of said first relay, a polarized train governing master relay having two windings arranged when energized to swing the armature to opposite positions, a circuit for said master relay including a front contact of said first relay and a back contact of said second relay, and means operating when the armature of said master relay is swung to either position to connect into the circuit for such relay the winding which swings the armature to the other position.

6. Railway tra'fiic controlling apparatus comprising means for periodically supplying direct current to a track rail, a train carried receiver winding located in inductive relation to said rail, a circuit controlled by said receiver winding and including a source of current as well as a resistance element, a tube connected across said resistance element and characterized by a normally high resistance which becomes greatly reduced when the voltage applied to the tube exceeds a given value, a relay connected with said tube and normally de-energized but energized when the resistance of said tube is reduced, and train governing apparatus controlled by said relay.

7. Railway traffic controlling apparatus comprising means for periodically supplying direct current to a track rail, a train carried receiver winding located in inductive relation to said rail, a circuit controlled by said receiver winding and including a source of current as well as a resistance element, a tube connected across said resistance element and characterized by a normally high resistance which becomes greatly reduced when the voltage applied to the tube exceeds a given value, a relay connected with said tube and normally ole-energized but energized when the resistance of said tube is reduced, a second relay having a back contact included in the circuit for said first relay, a circuit for said Qsecondrelay controlled bya front c ntact Of 7 said first relay, a polarized train governing master'relay having two windings arranged when energized to swing the armature to 0p posite positions, a circuit for said master relay including a front contact of said first relay and a back contact of said second relay, and means operating when the armature of said master relay is swung to either position to connect into the circuit for such relay the winding which swings the armature to the other position. I

8. Railway trafiic controlling apparatus comprising means for periodically supplying direct current to a track rail, a train carried receiver winding located in inductive relation to said rail, a circuit controlled by said receiver winding and including a source of current as well as a resistance element, a grid glow tube having its anode and grid connected across said resistance element, a plate circuit for said tube including a relay, a second relay having a back contact included in the circuit for said first relay, a circuit for said second relay controlled by a front contact of said first relay, a polarized train governing master relay having two windings arranged when energized to swing the armature to opposite positions, a circuit for said master relay including a front contact of said first relay and a back contact of said second relay, and means operating when the armature of said master relay is swung to either position to connect into the circuit for such relay the winding which swings the armature to the other position.

In testimony whereof I aiiix my signature.

LEWVIS L. NETTLETON. 

